CURRENT CONTROLLER FOR INDUCTIVE LOAD

摘要

A current controller capable of driving a large inductive load at a low supply voltage and improving the response characteristic of the inductive load in view of current control. When the voltage detected by an absolute-value circuit (10) indicating the current flowing through an exciting coil (1) as inductive load exceeds a reference voltage, transistors (3a and 3b) respectively connected between DC power sources (2a and 2b) and an exciting coil (1) are disconnected and a capacitor (5) is charged up to a high voltage by the magnetic energy stored in the exciting coil to suddenly decrease the exciting current flowing after the transistors are disconnected. When the detected voltage lowers to a predetermined value, the transistors are turned on, and the voltage charged in the capacitor and the DC supply voltage are applied to the exciting coil. Thus, the exciting current quickly rises and thereby, the response characteristic of the exciting current to the reference voltage can be improved without applying the high voltage from the DC power source to the inductive load.